Source: NASA's Earth Observatory. Image acquired April 15 2010.Volcanic Ash Plume across the North Atlantic, 2010In April 2010 a volcanic eruption in Iceland released a large quantity
of ashes that spread towards Western Europe due to dominant wind patterns
(see above photo).
Volcanic ash is composed of tiny jagged particles of rock, mostly silicates,
which are highly abrasive. If an airplane flies through such an ash
cloud the result can be an engine failure. The problem was compounded
by the fact the volcanic ash cannot be detected by an aircraft weather
radar and that the ashes drifted at altitudes from 20,000 to 36,000
feet, which corresponds to the cruising altitude of most commercial jets.Therefore, on Thursday April 15 aviation authorities started to shut
down airspaces and airports as a precautionary measure. The outcome
was the largest natural disruption of air travel in history with the
closing of the majority of European airports, including mega hubs such
as London, Paris, Brussels, Frankfurt and Amsterdam. The only exceptions were airports
in the southern part of Europe, such as in Spain, Greece and Southern Italy.
The plume also crossed the main great circle transatlantic air routes,
closing many of them. Additionally, due to cancelled flights, the
whole global air transport system was disrupted. This disruption was
unique by its regionalism and that it only impacted directly
one specific mode, but with substantial indirect impacts on others modes,
mainly rail. The only equivalent disruption relates to when the American
airspace was shut down for three days after the events of
September
11 2001.The disruptions of the European airspace of April 2010 had
various consequences on both the air passengers
and freight markets:

Passenger market disruptions. The shut down
of most European airports impacted 29% of the global air market, which was equivalent
to 1.2 million passengers per day. About 100,000 flights were
cancelled costing the industry $1.7 billion. This involved stranded passengers
unable to find a ready alternative to get back home, cancelled business
meetings and conferences and a drop in tourism for the world's largest
touristic market.

Freight market disruptions. Many supply chains
of high added value were disrupted, including electronics, car parts
and fresh produce. Parcel delivery on which many businesses depend
for their management and transactions were also seriously disrupted.
The impacts on value chains were particularly acute since air freight
is geared towards the support of just-in-time strategies were inventory
levels are kept low. The time lag between when the disruption
occurs and when supply chains starts to be impaired and shut
down thus tends to be short. A salient example concerned the fresh flowers
and produce industries in developing countries (Africa, Latin
America and the Middle East). Kenya, which exports
about 1,000 tons of fresh flowers and produce per day by air transport,
mostly to Europe, saw a complete stop of its production,
a lot of it going to waste because of a lack of cold storage facilities
and short shelf life.

On Monday April 19, air traffic started to resume as airports and
airspaces were gradually re-opened. It took however several days for
the global air transport market to return to normal operating conditions,
mainly due to a backlog of passengers and freight shipments. Although
this event was unique, it is likely that such occurrences may happen again
in the future. It only took 9 years after the events of September
11 2001 to see a disruption of a similar scale taking
place, although of completely different causes.